1. Field of the Invention
The present invention relates to a water purifier for removing noxious pollutant substances contained in fresh water such as tap water to purify the water, and more particularly to a water discharging control device for a water purifier, being capable of correctly determining an appropriate time for finishing the water discharging operation on the basis of the residual amount of contaminated water in a water tank, thereby correctly performing the water discharging operation for purified water which stored in the water tank for a long time.
2. Description of the Prior Art
Typically, water purifiers are used to remove noxious pollutant substances contained in fresh water such as tap water, in order to supply purified water. They are classified into a natural filtering type, a forced filtering type, and ion exchanging resin type and a reverse osmotic type in accordance with the methods for purifying water.
Water purifiers of the reverse osmotic type, which force fresh water to pass through an artificial osmotic membrane (reverse osmotic filer) while applying pressure to the fresh water, can remove heavy metals, bacteria, cancer-causing materials and the like contained in the water, thereby purifying the water. Since the reverse osmotic water purifiers can supply pure water containing only dissolved oxygen, they have been used in fields such as super-pioneering scientific industry, medical science or cleaning for super-precise electronic elements. Recently, such reverse osmotic water purifiers have widely been used as domestic water purifier for supplying drinkable water.
FIG. 1 illustrates a conventional reverse osmotic water purifier having the above-mentioned function. As shown in FIG. 1, the water purifier includes a purifier body 4 which is connected to a faucet 1 via a water supply pipe 3. This water supply pipe 3 is coupled to the faucet 1 by means of an adapter 2. The purifier body 4 is supplied with fresh water, such as tap water, from the faucet 1 through the water supply pipe 3. The fresh water introduced in the purifier body 4 passes through a pre-processing filter 5 disposed at the rear portion of the purifier body 4. The pre-processing filter 5 removes various harmful organic chemical materials such as chlorine components and the like from the water passing therethrough. The water emerging from the pre-processing filter 5 then passes through a water supply valve which controls the amount of the water supply. The water from the water supply valve is then introduced in a pressure pump so that it can be pressurized to a certain pressure level. The pressurized water is then fed to a membrane filter 6 including a plurality of membranes (not shown). While passing through the membranes, the water becomes free of heavy metals, bacteria, cancer-causing materials and the like contained therein. The water emerging from the membrane filter 6 then passes through a post-processing filter 7 by which odorous substances such as noxious gas are removed from the water.
The water, which has a pleasant taste as it becomes free of odorous substances such as noxious gas while passing through the post-processing filter 7, is then fed to a water tank 9 through a water supply port 8.
When the purified water is supplied in the water tank 9, it is determined whether the amount of water contained in the water tank 9 corresponds to a full water level (namely, the maximum water amount required to shut off the supply of purified water to the water tank) or an empty water level (namely, the minimum water amount required to supply purified water to the water tank).
Where the amount of water contained in the water tank 9 corresponds to the full water level, the supply of purified water to the water tank 9 is shut off. On the other hand, where the amount of water in the water tank 9 corresponds to the empty water level, the water tank 9 is supplied with purified water. In such a manner, the water tank 9 is always stored with a constant amount of purified water.
The purified water stored in the water tank 9 can be discharged through a discharge port 11 by manipulating a water discharge lever 10 so that it will be drinkable.
FIG. 2 is a detailed circuit of a water discharging control device in accordance with the prior art.
As shown in FIG. 2, the device includes a water discharging manipulating unit 13 having a water discharging switch SW, a resistor R and a capacitor C, and a microcomputer 15 for controlling the water discharging operation on the basis of a signal output from the water discharging manipulating unit 13. The microcomputer 15 receives the signal through an input terminal IN thereof.
The device also includes a valve driving unit 17 having an inverter IC, a relay RY, diodes D1 and D2, and a water discharging valve 19 so that purified water in the water tank 9 is discharged by a control signal output from an output terminal OUT of the microcomputer 15.
The water discharging control device having the above-mentioned construction is operated as follows.
Once the water discharging switch SW is turned on, and then the microcomputer 15 receives a low level signal through the input terminal IN thereof. Therefore, the microcomputer 15 outputs a high level signal to the valve driving unit 17 through the output terminal OUT thereof, so that purified water in the water tank 9 is discharged.
The high level signal output from the microcomputer 15 is inverted to the low level signal by the inverter IC, thereby being applied to the relay RY. Therefore, a contact terminal RYc of the relay RY is closed, thereby being applied the DC voltage Vcc3 to the water discharging valve 19 through the contact terminal RYc. Therefore, the water discharging valve 19 is opened, thereby being discharged contaminated water in the water tank 9 through a water discharging pipe (not shown).
Meanwhile, the microcomputer 15 determines whether or not the water discharging time is lapsed a predetermined time previously stored therein while being discharged the putified water. The time is counted by a timer previously equipped in the microcomputer 15.
As a result, when the microcomputer 15 determines that the water discharging time has been reached the predetermined time, the microcomputer 15 output a control signal to the valve driving unit 17, thereby closing the water discharging valve 19.
In accordance with the control signal, the valve driving unit 17 cuts off the source voltage being applied to the water discharging valve 19, thereby closing the water discharging valve 19.
The above-described prior art, however, the amount of contaminated water in the water tank does not comply with the predetermined time previously stored in the microcomputer because the water discharging operation is performed for time as many as the predetermined time. That is, there are frequent occassions when it becomes to perform the water discharging operation even after the contaminated water in the water tank is completely discharged.
On the other hand, there are frequent occassions when it becomes not to perform the water discharging operation, nevertheless, the contaminated water in the water tank is not completely discharged.